1. Field of the Disclosure
This disclosure relates to a backlight unit, and more particularly to a backlight unit which prevents an initial driving malfunction, and a liquid crystal display device having the same.
2. Description of the Related Art
Display devices used for computer monitors or TVs include self-light-emitting devices such as organic light emitting displays (OLEDs), vacuum fluorescent displays (VFDs), field emission displays (FEDs), and plasma display panels (PDPs), as well as non self-light emitting devices such as liquid crystal displays (LCDs). A general LCD device includes two substrates having electric field generation electrodes and a liquid crystal layer having dielectric anisotropy and interposed between the substrates. When a certain voltage is applied to the electric field generation electrodes, an electric field is generated in the liquid crystal layer. The strength of the electric field is adjusted by changing the voltage. Thus, a desired image is displayed by controlling the transmissivity of light passing through the liquid crystal layer.
The LCD device includes a data driver, a gate driver, and a backlight unit. The data driver externally receives image data, generates the data signal of a specific pixel and supplies the generated data signal to a data line of an LCD panel The gate driver generates a gate signal to drive the pixels of the LCD panel by one line and supplies the generated gate signal to a gate line of the LCD panel The backlight unit is disposed on the rear surface of the LCD panel and provides light.
Cold cathode fluorescent lamps (CCFLs), external electrode fluorescent lamps (EEFLs), or light emitting diodes (LEDs) are used as the light source of a general backlight unit. Recently, the EEFLs are widely used as the light source of a backlight unit due to their merits such as a long lifespan.
If the EEFL included in the direct type backlight unit of the large LCD device is left in the darkness or at a low temperature, gas injected into the EEFL changes into a basic state. As such, the EEFL does not light up when the LCD device is initially driven. In other words, an initial driving malfunction occurs in the EEFL and the backlight unit having the same.